Inter and intraspecies variability of terpene profiles of four spruce species growing in the Czech Republic: a chemotaxonomic study

Inter and intraspecific variability in terpene abundance is a key marker in chemotaxonomic studies of conifers. Quantitative distribution as well as qualitative trends in terpene abundance in Norway spruce, Siberian spruce, blue spruce, and Sitka spruce were identified using cold solvent extraction combined with gas chromatography/mass spectrometry. The spruces species showed a high variability of terpene profiles within studied parts of the trees but always the same qualitative trend corresponding to the assignment to Picea and Casista sections. While in Norway spruce and Siberian spruce (section Picea) α-pinene, camphene, bornyl acetate dominated in the needles, α-pinene, β-pinene, and pimara-7,15-dien-3-one were the most abundant in the resins from tree trunks. In contrast, α-pinene, β-pinene, and methyl abietate dominated in the cones. While limonene, camphene and camphor dominated in the needles of section Casista, high amounts of α-pinene and thunbergol were reached in the resins from tree trunks. In contrast, α-pinene, β-pinene, and Labda-8(20),14-dien-13-ol dominated in the cones. Between P. abies and cultivars ‘Cupressina’ and 'Finedonensis' a significant homogeneity in the qualitative trends of terpene abundance was revealed. The distinguishing terpene was diterpene thunbergol. Significant seasonal variability in the abundance of the monoterpenes tricyclene, β-pinene, and bornyl acetate, and the sesquiterpene germacrene D-4-ol was found. In conclusion, the results confirmed high chemotype and genotype dependence of spruce species in terpene abundance, with the exception of β-phellandrene in the 'Finedonensis', whose abundance was highly unstable.